Code:public static int StringMatch(string baseStr, string compStr) { int count = 0; int index = 0; for (int i = 0; i < baseStr.Length; i++) { for (int j = 0; j < compStr.Length; j++) { if (baseStr[i]==compStr[j]) { index = i; // i need to return indexof the first character of basestring count++; } if(count==compStr.Length) { Console.WriteLine("string match"); } } } return index; } static void Main(string[] args) { string txt = "fftf kargi kargi"; string phrase = "kargi"; int res = StringMatch(txt, phrase); Console.WriteLine(res); } } }